Oral Health and CKD in Brazil: A Population-Based Analysis of the 2019 National Health Survey

Background: Evidence suggests a bidirectional relationship between oral health and chronic kidney disease (CKD), but data from low- and middle-income countries remain limited. This study examined the association between oral health indicators and CKD in a nationally representative sample of Brazilian adults. Methods: We analyzed data from the 2019 Brazilian National Health Survey (PNS), which used a stratified, multistage cluster sampling design. The outcome was self-reported CKD. Exposures included self-rated oral health, tooth loss, toothbrushing frequency, and eating difficulty due to oral conditions. Survey-weighted logistic regression estimated adjusted odds ratios (ORs) and 95% confidence intervals (CIs), controlling for age, gender, race/ethnicity, diabetes, and hypertension. Results: The sample included 279,382 adults, representing over 209 million people. Poor self-rated oral health was significantly associated with CKD (OR: 2.15; 95% CI: 1.56–2.97). Additional associations were observed for tooth loss (OR: 1.30; 95% CI: 1.00–1.69), low toothbrushing frequency, and eating difficulty (moderate: OR: 1.43; intense: OR: 2.06). Fewer than half had visited a dentist in the previous year, and only 22.6% used public dental services. Conclusion: Tooth loss, poor hygiene, and oral health–related functional limitations were associated with CKD in this Brazilian population. These findings highlight the importance of including oral health in chronic disease prevention policies and expanding access to integrated dental care, especially in under-resourced health systems.